Sattari Hamed, Takabayashi Alain Yuji, Zhang Yu, Verheyen Peter, Bogaerts Wim, Quack Niels
Opt Lett. 2020 Jun 1;45(11):2997-3000. doi: 10.1364/OL.394470.
Directional couplers are extensively used in photonic integrated circuits as basic components for efficient on-chip photonic signal routing. Conventionally, directional couplers are fully encapsulated in the technology's waveguide cladding material. In this Letter, we demonstrate a compact broadband directional coupler, fully suspended in air and exhibiting efficient power coupling in the cross state. The coupler is designed and built based on IMEC's iSiPP50G standard platform, and hydrofluoric (HF) vapor-etching-based post-processing allows to release the freestanding component. A low insertion loss of 0.5 dB at =1560 and a 1 dB bandwidth of 35 nm at =1550 have been confirmed experimentally. With a small footprint of 20µ×30µ and high mechanical stability, this directional coupler can serve as a basic building block for large-scale silicon photonic microelectromechanical systems (MEMS) circuits.
定向耦合器作为高效片上光子信号路由的基本组件，在光子集成电路中得到了广泛应用。传统上，定向耦合器完全封装在该技术的波导包层材料中。在本信函中，我们展示了一种紧凑的宽带定向耦合器，它完全悬浮在空气中，并在交叉状态下表现出高效的功率耦合。该耦合器基于imec的iSiPP50G标准平台进行设计和制造，基于氢氟酸（HF）气相蚀刻的后处理允许释放独立组件。实验证实，在λ = 1560时插入损耗低至0.5 dB，在λ = 1550时1 dB带宽为35 nm。这种定向耦合器具有20µ×30µ的小尺寸和高机械稳定性，可作为大规模硅光子微机电系统（MEMS）电路的基本构建模块。
